Four of the five studies proposed in this application depend on the capability to measure bone mineral by a non-invasive technique in either humans (Projects 4,5;) or animals (Projects 2 and 3) (Table 1). Human measurements include regional analyses of the spine, 3 regions of the hip (Femoral neck, Ward's triangle and Trochanter), and 3 regions of the radius (ultra-distal, mid-distal and proximal), in addition to total body bone mineral.